This invention relates to an air venting device for an automotive vehicle enclosed housing, and more particularly to a one piece air venting cap adapted for use with a flexible tubular member.
The prior art is replete with air bleeding or venting devices for an automotive vehicle enclosed housing, such as an axle housing or a gear housing. The U.S. Pat. No. 4,506,562 issued Mar. 26, 1985 to Yamaura et al. discloses a unitary air bleed device of an elastomeric deformable material and has an integrally formed head portion with a vent hole and a cylindrical portion. The cylindrical portion is formed with a connecting passage which communicates with the vent hole of the head portion. The deformation of the air bleed device permits it to be mounted to an enclosed housing by press fitting. When mounted, the cylindrical portion extends into the housing in such a direction to prevent the oil entry into the connecting passage.
The U.S. Pat. No. 4,595,118 issued June 17, 1986 to Azuma et al. discloses an air-breather device for an oil casing filled with oil and accommodating a driving mechanism such as a vehicle differential gear casing. The air-breather device comprises a cylindrical breather plug deflector attached to the wall of the oil casing and having an end opening into the oil casing, a breather plug having an open end opening into the breather plug in the oil casing and the other open end which opens to the outside of the oil casing. The other open end is normally closed by a spring-urged cover, and a baffle plate is attached to the breather plug deflector on the upstream side thereof so as to intercept the flow of oil which tends to flow into the opening of the end of the breather plug within the casing.
An example of a currently used vent cap for an automotive axle housing is shown in FIGS. 1 and 1A and denoted as prior art. The vertical cross section of FIG. 1 shows a vent cap assembly 10' comprising a cylindrical body member 12' and a cap member 14'. The body member 12' has a hollow cylinder 16' defining a hollow chamber 18' and having its upper edge formed with a peripheral collar portion 20' which extends radially outwardly so as to overhang the cylinder outer surface. The cylinder lower end is formed with an axially extending hollow tubular stem portion 22' communicating, via central aperture 24', with the cylinder chamber 18'. A flexible hollow conduit 26' is shown with one end 28' thereof telescopically press fitted on the stem portion 22' with the conduit other end adapted for sealing connection to an axil housing or the like (not shown).
The cap member 14' has a depending skirt portion 30' having a diameter a predetermined dimension larger than the cylinder diameter. The skirt portion 30' is formed with an internal circumferential rib 32' sized such that, upon the cap member 14' being telescoped on the upper end of the cylinder 12', the rib 32' is resiliently snap-fitted over the collar portion 18'. In this manner the cap member 14' is captured on the cylinder 12' so as to concentrically surround the cylinder upper open end 34' with the cap member 14' adapted to move axially or float relative thereto from its rest position shown in FIG. 1. It will be noted that the collar portion 18' has a plurality of spaced lugs 36' formed thereon adapted to space the cap member top open end 38' vertically above the cylinder upper open end 34'. The lugs 34' establish air passage gaps insuring minimal communication between the axle housing and the atmosphere with the cap member in its rest mode. Further, as seen in FIG. 1A, the collar portion 18' is formed with a pair of diametrically opposed slots 40' allowing air flow between the axle housing and the atmosphere. The rib 32' is axially spaced from the collar shoulder 40' a predetermined dimension such that upon the internal pressure of the axle housing being increased the cap member 14' is lifted to open the upper open end opening of the vent cap cylinder 12' overcoming the gravity force on the cap member 14' allowing the internal high pressure of the axle housing to be relieved through the gap formed between the collar brim and the cap member.